Slummies, I'm actually looking for a replacement for the 18-55 - I only want to carry 1 lens around generally so need something with a little more zoom than 55. So its general purpose. 1st prize would be the canon 18-200 but its pricey. So, if I have to I will keep 2 lenses and 18-55 and 70-300.

What are you thoughts?

ps. I need the zoom for shooting things like my daughter at sports day, etc!!!!

You can get the 18-135 for around the R2000 mark on outdoorphoto.co.za in their classifieds section. I sold mine 3 weeks ago for R1800. Check around there for second hand lenses. Most of the 18-135 that are sold is pretty much brand new. People got them as kit lenses and have upgraded.

1. USM/HSM has to do with the speed of the focus and I think also something to do with the sound of the motor. HSM typically more noisy than USM.

2. For a zoom lens, you NEED IS, unless you will be mostly using a tripod, etc. Go to a shop and test an IS zoom lens, say 300mm with IS and without. Full zoom and try and hold the lens in one place. I guarnatee you will feel sea sick without the IS and you therefore wont get sharp images.

USM/HSM is the motor that drives the auto focusing system. USM/HSM is a lot quieter than the normal ones and faster when it comes to focusing. Canon does not have IS in the body. IS is only via the lens. That is why you get non IS and IS lenses. On any zoom I would say that you need IS unless you are going to use a tripod every single time. The only lenses where you dont need IS is the F2.8 or faster lenses with s short focal length like 15mm etc.

Sigma is not bad at all. Some of their lenses like the 50mm F1.4 is actually better than the Canon 50mm F1.4.

Did you get the 18 or the 28-135 Sean? I had the the 18-135. Sold it when I got the 24-105. Before I sold it I did a comparison between the two. The 18-135 was just as sharp, if not a tad sharper than the 24-105 in the center. But it did go soft around the edges very quickly. The 18-135 is a very nice and sharp all round when used at F7.1-F8.

There are a few 18-135 going for sale on outdoorphoto. The latest one is going for R2200. Sold mine for R1800 4 weeks ago.